It is well known that soft drinks typically comprise a combination of syrup and soda, the latter being the main ingredient of such drinks, and constituting carbonated water which is generated by the entraining of carbon dioxide (CO.sub.2) gas into water under pressure.
If an insufficient quantity of CO.sub.2 gas is entrained in the water, the soda or resulting soft drink has a "flat" taste, the same typically being quite unacceptable. It is well known in the art that it is important that carbonated water be maintained at a cool or cold temperature, approaching the freezing point of water. The colder the soda, the more CO.sub.2 that can be maintained therein, providing the soda with a more lively taste. Additionally, when the soft drink is dispensed the temperature of the soft drink, being above the freezing point of the ice onto which it is dispensed, will typically melt some of the ice until the ice and soft drink combination reaches a point of equilibrium. It is most desirable that the soda be as cold as possible so that the tendency to melt ice is reduced, particularly since the melting of ice dilutes the drink not only with respect to its sweetness or brix level, but also renders the drink flat by reducing the concentration of CO.sub.2 therein.
Since it is desirable to keep the soda source as cold as possible, it was previously known to place the soda tank in the ice bin of the soft drink dispenser itself. However, this ice bin provides the source of ice placed in the cups in which the soft drinks are served to customers. Accordingly, health agencies now prohibit such placement of the soda tank within the ice bin of the consumable ice.
Presently, the carbonation or soda tank is kept apart from the ice bin itself. The water used for generating the soda is run through a cooling plate which lowers the temperature of the water to a level depending upon the original temperature of the water itself. This prechilled water is then introduced into the soda tank where CO.sub.2 gas is applied under a pressure head to entrain the gas in the water. At the time of dispensing the soft drink, soda from the soda tank is again run through the cooling plate so that the soda is cool at the time of dispensing. Such present systems are highly inefficient, typically resulting in soda dispensing temperatures much higher than optimum.
In the prior art, cooling of the soda was performed dynamically and in stages. The water was cooled before it entered the soda or carbonation tank, and the soda was cooled again immediately prior to dispensing. Both cooling operations were typically performed by running the water through a cooling plate before entering the carbonation tank, and by running the soda from the tank through the cooling plate to the dispensing head. No cooling was performed in the carbonation tank itself which, being uninsulated, allowed the soda to warm toward ambient.
The prior art fails to teach a soda tank serving as both a generator and cooler and in which the soda is continually cooled by the ice in the ice bin while being maintained apart therefrom. Further, the prior art fails to teach a soda tank which is capable of efficiently generating and maintaining soda while assuring a cool dispensing temperature to prevent dilution of the resulting soft drink through the melting of ice.
Indeed, the prior art fails to teach the cooling of soda in a soda tank apart from the ice bin, while employing the ice bin as the cooling media, and in which the cooling efficiency is independent of the level of ice within the ice bin. Further, the prior art fails to teach the implementation of the ice bin as the cooling media and in which the ice bin walls are so insulated and isolated from the soda tank to preclude sweating of the walls.